ROSH Gastrointestinal Practice Exam

What laboratory result indicates acute hepatitis A infection in a 15-year-old boy with jaundice?

1. Anti-Hepatitis A Virus IgG positive

2. Anti-Hepatitis A Virus IgM positive

3. Elevated serum alkaline phosphatase

4. Elevated serum alanine aminotransferase, aspartate aminotransferase, and bilirubin

The correct answer is: Elevated serum alanine aminotransferase, aspartate aminotransferase, and bilirubin

The identification of acute hepatitis A infection hinges on the presence of specific laboratory markers. In this case, the indication of acute infection is primarily tied to the presence of Anti-Hepatitis A Virus IgM. However, the choice indicating elevated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin reflects the typical biochemical changes associated with acute hepatitis. When a person is infected with the hepatitis A virus, liver inflammation occurs, which leads to the release of liver enzymes into the bloodstream. Hence, elevated serum levels of ALT and AST are markers indicating hepatocellular injury and inflammation. Additionally, jaundice, a common symptom of acute hepatitis, corresponds with increased bilirubin levels due to liver dysfunction. Elevated alkaline phosphatase may suggest cholestasis or biliary obstruction, which is more commonly associated with other types of liver disease rather than specifically acute hepatitis A infection. Therefore, assessing the combination of elevated liver enzymes and bilirubin levels provides a clearer picture of acute hepatitis A infection. In summary, the laboratory result indicating elevated serum alanine aminotransferase, aspartate aminotransferase, and bilirubin signifies liver inflammation and dysfunction typical of acute hepatitis A, aligning closely with the clinical